Graining



Marel: 23, 1937. w G, BIHPER ET AL 2,074,532

TTORNEYS w. "G. lall-LER Er AL 2,074,532

GRAINING 'March 23, 1937.

File'd June 27, V1956 s sheets-sheet 2 INVENTORS March 23, 1937. w. e..l BIHLER ET Al. 2,074,532

4 GRAINING Y Filed June 27. 1936 3 Sheets-Sheet 3 ATTORNEYS INVENTORS.

Bmw i r I Patented Mar. 23, 1937 sTA'rss GRAINING Walter G. Bihler and Howard J. Schuldt, Detroit,

Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 27, 1936. serial Nc. 87,691

J 12 Claims.

This invention relates to graining. It is now quite common to grain hollow-ware such as containers, boxes and particularly the garnish molding used on `automobile windows by means of a machine having upright rolls and a horizontal table. The work is placed over the end of one roll or one set of rolls and rests on the table.

If the work is being `grained on the inside, it has to be placed over a roller set, to-wit: one translo fer impression roll and one engraved roll. If the Work is to be grain on the "outside, it is placed over the pressure roll. So far as we are aware, operations of this kind have always heretofore been done with plain cylindrical impres- 15 sion rolls. This has made it dimcult to get good grain eiects on rounded surfaces such as the turned in surfaces of the garnish molding. If the operator presses the rounded surface deeply into the transfer roll, then the graining lines are somewhat distorted.

One way of meeting the difficulty of the rounded edge portions of the garnish molding has been to separately grain each edge as well as the intermediate zone of the molding, this requiring three separate passages of the molding l over a transfer roll. Another way has been to grain the center zone by the usual upright rolls and then smoke the edges, that is, spray a dark lacquer on the edges to cover the lack of grain effects at the edges.

It is the object of the present method and machine to grain a rounded surface, particularly the rounded surface of the garnish molding which is exposed to view, with a graining eiect which 35 is substantially undistorted and which can be performed in the same operation which grains the center zone of the molding. To this end, we

use the apparatus and the method hereinafter detailed.

In the drawings: y Fig. 1 is a side elevation of the machine, partly in section. K

Fig. 2 is a plan view. Fig. 3 is a diagrammatic view showing how the molding goes through the rolls. n

Fig. 4 is a detail vertical section through the I rolls.

Fig'. 5 is a section on the line 5--5 of Fig. 4. Fig. 6 is a plan view ofthe devices shown in Fig. 4.'

Fig. '7 is a section on the line 1-1 of Fig. 4. Referring to Fig. 4, I is the etched roll having etched thereon a photogravure-reproduced image, made by photographing stained natural wood, making a positive from the negative. thenl exposing a carbon tissue coated with gelatine which has been sensitized by bi-chromate of potassium solution to light through a screen, then exposing the tissue to light through the positive. This light rendersA the portions of the sensitized 5 gelatine which have been exposed to the light insoluble in water. When the carbon tissue has been squeegeed upon the roll to be engraved, the tissue backing may be soaked off with warm water as well as the soluble gelatine. This leaves 10 the insoluble portionsthat have been exposed to light as an acid resist which can resist the penetration of the etching fluid which is usually ferrie chloride, where a copper plate or roll is used. This affords an intaglio image of the article 15 photographed, with alarge number of minute pits or pockets to take the ink. This is the wellknown photogravure process which has been used for years in printing the illustrated supplements of newspapers and the better pictorial reproduc- 20 tions in magazines. This photogravure process has been employed for quite some time in rey producing graining-ei`iects from natural wood. This etched roll is contacted with a soft elastic or gelatine roll 2 which has been common for 25 years in so-called offset printing. The work is shown at W and this is pressed up against the gelatine or impression roll by a pressure roll 3 which is operated byhthe foot pedal d through the inner connecting link and crank members 30 that are plainly shown in Fig. 1, described hereinafter. The set-up of etched roll l, transfer roll 2, and pressure roll 3 is nicely shown in Fig. 3 where it is seen how this group of rolls is related to the work W. l

Now so much of the machine is old practice. The improvement here claimed involves the end formation of the transfer roll and the instrumentalities for guiding it into lproper relation with the etched roll and bending it over a curved 40 surface. 'Ihis is nicely shown in Fig. 4 where it will be seen that the elastic transfer rollextends way beyond its core 5 contrary to the usual practice. This unsupported end extension is tapered f outwardly. A conical guide roll 6 ts linto this 45 tapered end extension and keeps the elastic roll pressed against the engraved roll, and segments 30 keep the end extensionn from being unduly distorted by stretching. Diagrammatically opposite this guide roll 6 is a special pressure roll 1 50 contoured to press and guide the tapered end extension of the transfer roll over the curved edge of the work as is plainly shown in Fig. 4. This roll is carried on a movable support 8 which is guided up and down in a fixed support 9. This 55 membe1l 8 has a dovetail straddle of the fixed support 9 as shown at I0 in Fig. 6. The walking beam Il connects this movable support with a reciprocating rod I2l which connects through the bell cranks and leverage plainly shown in Fig. 1 with the pedal 4 so that every time the pressure roll 3 is pressed in engagement with the work simultaneously the pedal operates the levers I3 contact with the contoured surface with. not a the work at one time provided the foot pressure is exercised on the left hand half of the pedal.

However, if the foot pressure. is exercised on the right portion of the foot pedal as shown in Fig. 1, then only the rod 3l which controls the pressure roll 3 will be operated and the auxiliary roll 'l will be released and allowed to rise. This is desirable where molding is being grained which contains on part of the molding, a panel or apron such as is very often used on the lower sash of a vwindow molding. This restores the roll to its cylindrical form in place of turning out the end ofthe roll over the curved molding. Hence, the operator When the work comes to the apron portion can simply shift his foot over to the right side of the pedal and this will release the auxiliary roll. It will be noted that the lever 32 has a 'cam-like portion 33 that engages with the member 34 on the lever 35 which controls the pressure roll 3. This firmly holds the pressure roll in engagement with the work as it constitutes a substantially irreversible operating connection.

What we claim is:

1. The method of printing on contoured surfaces with an elastic roll having the elastic material overhanging at the end of the roll which comprises the forcing of the overhanging end of the elastic material into a contour approximating the contour of the surface to be printed upon and into contact with such surface.

2. The method of printing on contoured surfaces with an elastic roll having the elastic material projecting at the end of the roll which comprises the folding or turning of the projecting elastic material into contact with the contoured surface.

3. The method of printing onvcontoured surfaces with an elastic roll having the elastic material overhanging at the end of the roll which comprises the folding or turning of the overhanging elastic material into contact .with the contoured surface by a pressure roll.

4. The method of printing on contoured surfaces with an impression roll having an end overhanging the core and tapered inwardly from the outside tothe end of the core which comprises applying the vWork to the surface of such elastic impression roll by' means of pressure substantially perpendicular to the surface of the Work, then simultaneously applying an oblique pressure to the tapered inside of the overhanging end of the elastic material of the impression roll, thus folding or turning said impression roll at this point down over the contour of the work.

5. An apparatus for graining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the etched roll and having a recess at the end of the -elastic material on the roll to provide a flexible overhanging end portion and means for turning the overhanging elastic portion of the roll outwardly over the contour of the work.

6. An apparatus for graining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the etched roll and having a recess at the end of the elastic material on the roll to provide a flexible overhanging end portion and means for turning the overhanging elastic portion of the roll outwardly over the contour of the work, said means comprising a contour roll.

7. An apparatus for graining or printing/'on contoured work, theA combination of an etched roll, an elastic transfer roll in contact with the etched roll and having a recess at the end-fof the elastic material on the roll to provide afexible overhanging end portion and means for turning the overhanging elastic portion of the' roll outwardly over the contour of the work, v/s/aid means comprising a pressure roll for turning the elastic material over the contour of the work and a guide roll for engaging the overhanging elastic portion and moving the same into contact with the inipression roll.

8. An apparatus for graining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the etched roll and having a recess at the end of the elastic material on the roll to provide a exible overhanging end portion, means for turning the overhanging elastic portion of the roll outwardly over the contour of the work comprising a contour roll, and means within the control of .the operator for applying said last mentioned means to the overhanging elastic portion of the impression roll 0r withdrawing the same therefrom.

9. An apparatus for graining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the etched roll and having' a recess at the end of the elastic material on the roll to provide a flexible overhanging end portion, means for turning the overhanging elastic portion of the roll outwardly over the contour of the work comprising a contoured roll, means within the control of the operator for applying said contoured roll to the overoverhanging end portion, means for turning the overhanging elastic portion of the roll outwardly over the contour of th-e work, said means comprising a contoured roll, means within the control of the operator for applying said contoured roll to the inside f the overhanging elastic portion of the impression roll or withdrawing said roll therefrom, and a second means within the control of the operator for applying a direct s tially perpendicular pressure to force the work into engagement with the elasticimpression roll, the

two said means within the control of the operator operable simultaneously by reason of being connected together.

11. An apparatus for graining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the over the contour of the work, said means comprising a contoured roll, means Within the ycontrol of the operator for applying said contoured roll to the inside oi' thev overhanging elastic portion of the impression roll or withdrawing said roll therefrom, and a second means within the control of the operator for applying a direct substantially perpendicular pressure to force the work into engagement with the elastic ini/pression roll, and pedaljxneans for operating the two controls simultaneously or optic i :111i operating only the said second means applying the perpendicular pres- 12. An apparatus forgraining or printing on contoured work, the combination of an etched roll, an elastic transfer roll in contact with the etched roll and having a recess at the end of the elastic material oli the roll to provide a exible overha end portion and means for turning the overhanging 'elastic portion of the roll outf wardly over the contour of the work, said means comprising a pressure roll for turning the elastic'- material over the contour of the work and a guide roll for engaging the overhanging elastic portion and moving the same into contact with the im`- pression roll, and means for engaging the inside of the end portion of the elastic material to prevent the distortion of the same between the guide roll and the said pressure roll which. turns the elastic material over the contour of the work.

WAL'I'ER G. B. Bowman J. scHUm'r. 

